Connectors for coaxial lines



R. B. CHESS May 30, 1961 2,986,720

CONNECTORS FOR COAXIAL LINES I Filed Aug. 11, 1958' FQL United States Patent Electric Company, Los Angeles, Calif., a corporation of California Filed Aug. 11, 1958, Ser. No. 754,373

1 Claim. (Cl. 339-.-89)

This invention relates to electrical connectors and more particularly to connectors for coaxial lines or cables.

It is a general object of this invention to provide an electrical connector comprising two complementary connector members which are adapted to be secured to the ends of cables of the coaxial type, respectively, for making an electrical connection of eicient and high power transfer Properties and. of reliable and rugged character.

The electrical connectors of this invention `are weatherproof, light in weight, of quick connect-disconnect type, and are designed to transmit high frequency currents lwith minimum impedance losses.

A11 important object of this invention is to provide a connector member for a coaxial line, which is adapted to be easily and quickly assembled upon the end portion of the coaxial line after the center conductor of the line has been connected to a contact element and the outer Conductor of the line has been exposed for electrical connection thereof to another contact element, whereby good electrical connection may be assured before assembly of the connector member components upon the end of the line.

Another object is to provide an electrical connector of the above mentioned character which may be easily and quickly assembled and disassembled without the use of special fasteners such as screws and the like and with a minimum of bonding points.

Further objects and advantages of this invention will appear in the following part of this specification wherein the. details of construction and mode of operation of a preferred embodiment are described with reference to the accompanying drawing, in which:

Fig. 1 is a side elevation showing two complementary connector members of this invention in engaged, or connected position;

Fig. 2 is a central longitudinal section through the connector members taken on line 2-2 of Fig. l; and

Figs. 3 and 4 are cross sections taken on lines 3--3 and 4-.4, respectively, of Fig. 2. Referring to the drawing in detail, numeral 10 designates one of a pair of complementary connectors, and for purposes of identification will be called a plug connector. The. other connector member is designated by reference numeral 11 and may be called a receptacle or jack connector. The plug connector is secured to the end portion of a section of coaxial line or flexible coaxial cable 12, and the jack connector is secured to the end portion of a coaxial cable 13.

Each of the coaxial cables is of conventional construction comprising a center conductor 16 (eg. strand of wires), a pliable dielectric tube 17 around the center conductor, a braided wire outer conductor 18 in tubular form around the dielectric, and an outside insulation jacket '19.

To prepare the end portions of the cable for connection thereof to their respective connector members, the end portion of the jacket 19 is cut oi'I along a transverse plane appearing as end 21, thereby to expose the braided outer conductor 18. Next, the end portions of the braid and of the dielectric 17 are cut oli? at 22 to expose the end portion 23 of the center conductor. A pin contact 24 is then secured over the end portion of the center conductor of cable I12. Such pin contact comprises a pointed end portion 25 of reduced diameter and a tubular shank portion 26 which receives the end of the center conductor, the inner end of the shank portion being in abutment with the end wall 22 of the dielectric. There is a hole 27 formed in the sidewall of the shank portion for receiving solder to secure the pin contact upon the center conductor.

The other cable 13 is prepared, similarly as described above for cable 12, for receiving a socket contact 29 upon the end of the center conductor. The socket contact has a tubular end portion 30 which is split longitudinally thereof at 31 for receiving the pin end of the pin contact.

The component parts of the plug connector will be described in the order in which they are placed upon the coaxial cable for assembling the connector member. Plug connector 12 comprises a tubular nut 34l having screw threads 35 externally thereof. An anti-friction washer ,36 is placed over the end of the cable next after the nut 34. A gasket sleeve 37 of elastomer material is then positioned around the cable. Following that is a cylindrical sleeve 38 placed around the end portion of the cable braid.

A ferrule having a tubular stem portion 40 and an annular end ange 41 extending radially outwardly from the outer end of the stern portion 40 is telescopically received around the dielectric 17 and Within the braid 18. The inner end 42 of the ferrule is preferably tapered, as shown, to provide a sharp annular end edge which lifts the braided conductor radially outwardly from the dielectric as the ferrule is pushed inwardly over the dielectric. The sleeve 38 is then moved axially back over the exposed surface of the braided conductor and serves to clamp the braid around the ferrule stem 40.

The plug connector member contains an outer contact 45 of tubular form by which the braided outer conductor of cable 12 become electrically -connected to the outer conductor of cable 13. The outer contact 45 is of stepped construction to provide a cylindrical skirt portion 46 having an external integral annular ange 47 around the inwardly disposedy end thereof, an inwardly extending annular step portion 48, and a tubular outer end portion 49 of reduced diameter. The outer end portion 49 has a plurality of axially directed slits 50 formed therein to divide the end portion 49- into a circumferentially arranged series of fingers 51 which may be ilexed radially inwardly to iit within the outer contact of the jack member as will be described more fully hereinafter. The outer ends of the fingers 51 are formed to provide a bead structure 52 extending circumferentially around the plurality of lingers to improve the electrical contact between the outer con tacts of the connector members.

The skirt portion of the outer contact 45 receives a cylindrical block insulator 53 having an axial bo-re 54 formed therethrough for receiving the pin contact 24. A preferred material from which to form the insulation block is Teflon. The block has small annular recesses 55 formed in each end face thereof to make each end face similar in configuration for purposes of mass production eiciency, and to provide for compensation of any electrical discontinuity between the dielectric 17 and the insulation block 53 as is well understood by those skilled in the art.

Reference numeral S7 designates the outside casing or tubular shell of the plug connector. It is of stepped construction on the inside thereof at 58 for accommodating the annular flange portions 41 land 47. The inner end portion of the shell is internally screw-threaded for mating plug member.

3 with the screw threads 35 of the tubular nut 34. Thus, after the component parts of the connector member have been arranged as described above upon the end portion of the cable, the shell may be tted over them and made tight by turning the tubular nut into the inner end portion of the shell. Axial movement of the nut inwardly of the shell will cause the elastomer gasket 37 to become 'compressed in an axial direction with the result that it will expand radially to press tight against the inside Wall of the shell and against the sleeve 38 and the outside surface of the jacket of the cable for the purpose of securing the cable tightly within the plug member. Furthermore, outward pressure of the elastomer Ygasket upon the ferrule flange 41 presses the flange into tight engagement with ange 47 of the outer contact to provide good electrical connection between the abutting annular faces of the flanges, the flange 47 being pressed against annular shoulder 58.

Most of the component parts of the jack connector are substantially identical and interchangeable with correspending parts of the plug connector. In the case of the jack connector, however, the outer contact 60 thereof is made to receive the fingers 51 of the outer contact of the Also, the shell 61 of the jack connector is longer in its outer end portion 62 than is the shell of the plug connector member to entirely enclose the outer contact 60 and to be received within a tubular coupling nut 63 on the plug connector.

The outer end portion of the shell of the jack connector is externally screw-threaded for mating with internal screw threads of the coupling nut at `64. The coupling nut is rotatable on the plug connector and is retained thereon by means of a snap ring 66 which is received within opposed annular grooves 67 formed on the outside surface of the plug shell and the inside wall of the coupling nut.

Referring again to the elastomer gasket 37, which serves to secure the cable within the connector member, it also functions to weatherproof the connector against seepage of air around the cable from the tubular nut end of the connector member. Weatherprooiing of the connector at the place of interengagement of the plug and jack members is provided by an elastomer seal ring 69 disposed within the plug member whereby the outer end of the jack shell will seat tightly upon the seal ring thus to seal the contacts of the connector from exposure to the outside atmosphere.

It is important for the purposes of this invention that the connector maintain true axial alignment of the end portions of the cable conductors. When in service in installations of the nature herein contemplated, the connector is subjected to severe vibrations and jars, which ordinarily would produce gap discontinuities and slight angular misalignments of the interengaged contacts. To the end, then, that the connector will be rugged and possess high strength for holding the contact parts in fixed relationship with respect to each other, the casings of the connector, i.e. shells 57 and 61, nuts 34, and coupler 63, are formed of metal. To make the connector of light weight, aluminum is a preferred metal from which to form the casing parts, and these are made insulated 4 i i and corrosive resistant by being anodized. The current carrying parts of the connector, i.e. ferrules 40, contacts 24, 29, 45 and 60, are preferably silver plated and formed of brass, copper or beryllium copper.

While the instant invention has been shown and described herein, in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claim.

What I claim is:

An electrical connector comprising al pair of complementary connector members for interconnecting the ends of two coaxial line sections, each of said coaxial line seotions comprising a center conductor, a dielectric surrounding said center conductor, and a braided wire tubular outer conductor surrounding said dielectric and having inside and outside cylindrical surfaces, each of said connector members including a housing having a centrally disposed axial bore therethrough and a tubular outer contact telescopically received within the rearward end portion of said bore and held against movement through the forward end of said bore, said tubular outer contact members each having an annular ange at the rearward end thereof, said coaxial line sections also being received through the rearward ends of the respective housing bores with their center conductors connected to center contact members disposed centrally within the forward ends of the respective bores and inwardly spaced from the respective tubular outer contact members, a metal ferrule received within each of said connector housing bores rearwardly of the respective tubular outer contact members, said ferrules each including a tubular stem portion surrounding the dielectric of the respective coaxial cable section and a forward annular end ange aligned with the respective outer tubular contact member and adapted to abut the annular contact ange at the rearward end thereof, the forward end of each outer conductor overlying the stem portion of the respective ferrule, a resilient sleeve disposed within each of said connector housing bores in surrounding relation with respect to the respective ferrule stem portion and with respect to the respective coaxial line section rearwardly of said ferrule flange, means Within said housings for axially compressing said sleeves to tightly engage said coaxial line sections and to force said ferrules into tight engagement with the adjacent tubular outer conductors, and means for interconnecting said housings in end-to-end relation with said center and outer contacts, respectively, in operative engagement.

References Cited in the le of this patent UNITED STATES PATENTS 2,241,419 Peters May 13, 1941 2,757,351 Klostermann July 31, 1956 2,785,384 Wickesser Mar. 12, 1957 2,870,420 Malek Ian. 2i), l1959 FOREIGN PATENTS 755,159 Great Britain Aug. 15, 1956 

